nth.

In medial and lateral dislocations there is at first considerable
tendency to re-displacement, and it is therefore necessary to secure
the joint in a box splint, specially padded, for about fourteen days,
massage being employed from the first, and movement commenced when the
splint is removed. It is usually about six weeks before the patient
can use the limb with freedom.

In compound dislocations, and in those complicated by injury to the
popliteal vessels, the question of amputation may have to be
considered.

#Dislocation of the Superior Tibio-Fibular Articulation.#--This joint
may be dislocated by twisting forms of violence applied to the foot or
leg, or by forcible contraction of the biceps muscle. The displacement
may be forward or backward, and the head of the fibula can be felt in
its new position with the prominent tendon of the biceps attached to
it. The movements of the knee are quite free, but the patient is
unable to walk on account of pain. Reduction and retention are, as a
rule, easy, and the ultimate result satisfactory. We have frequently
met with this injury accompanying compound fractures of both bones of
the leg resulting from railway and similar accidents.

By applying direct pressure over the displaced bone with the knee
flexed, the dislocation is easily reduced. It is kept in position by a
firm bandage or a light rigid splint.

#Total Dislocation of Fibula.#--Very rarely the fibula is separated
from the tibia at both ends and displaced upwards. Bennett of Dublin
has pointed out that in some persons the upper end of the fibula does
not reach the facet on the tibia--a condition which might be mistaken
for a dislocation.

INJURIES OF THE SEMILUNAR MENISCI

The semilunar menisci are two crescentic plates of white
fibro-cartilage, which lie upon the upper end of the tibia, and serve
to deepen the articular surface for the condyles of the femur. Each
cartilage is firmly attached to the tibia by its anterior and
posterior ends, and, through the medium of the coronary ligaments, is
loosely attached along its peripheral, convex edge to the head of the
tibia, the medial meniscus being connected also to the capsular
ligament of the joint. The tendon of the popliteus muscle intervenes
between the lateral meniscus and the capsule. The central, concave
edges of the menisci are thin and unattached.

The cartilages enjoy a limited range of movement within the joint,
passing backwards during fle